Method and apparatus for electrical control



@citn 8 135. F. W. GODSEY, JR

METHOD AND APPARATUS FOR ELECTRICAL CONTROL Filed April 30, 1.950

GOA/TROLL 0 05 VICE Patented Oct. 8, 1935 UNITED STATES METHOD AND APPARATUS FOR ELECTRICAL CONTROL Frank W. Godsey, In, New Haven, Conn, as-

signor to The Safety Car Heating & Lighting Company, a corporation of New Jersey Application April 30, 1930, Serial No. 448,768

18 Claims.

This invention relates to an electrical system and apparatus and to a method for achieving cyclic actuation, for example of a signaling device, at and for predetermined time intervals.

One of the objects of this invention is to provide a simple and thoroughly practical system and apparatus for dependably achieving periodic actuation of such a device as a visual or audible signal and to provide a thoroughly dependable control of the periods of time of actuation and inactivity. Another object is to provide an electrical system and apparatus capable of achieving, in a thoroughly dependable yet simple manner, the periodic actuation of a control member at precisely determined time intervals and, more particularly, to achieve cyclic actuation of a control member at successive periods, within each cycle, that may be the same or may bear any suitable relation to each other. Another object is to provide an apparatus of the above-mentioned character capable, in a simple and thoroughly practical manner, of a wide range of change in the relation of one period within a cycle to another period within the cycle of operation. Another object is to provide an electrical apparatus of the above-mentioned character in which, electrically, time intervals or periods of relatively great length may be produced. Another object is to provide a signaling system and apparatus in which repeated actuations of the signaling device may be achieved with thoroughly dependable control of the time intervals during which the signaling device is actuated and of the intervening time intervals; and more particularly to provide an electrical apparatus of this character in which it is possible to make efiective time intervals of a length greater than it has heretofore been possible. Another object is to provide a system and apparatus of the above-mentioned character that will be of inexpensive construction, rugged and thoroughly dependable in action, and well adapted to meet the varying conditions of hard practical use.

Another object is to provide a thoroughly practical method for achieving electrically relatively long periods of time or time intervals in the operation or actuation of an apparatus such as a signaling device and which method may be carried on in practice in a simple and practical manner and with thoroughly dependable and consistent results.

Other objects will be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements, arrangements of parts and in the several steps and relation and order of each of the same to one or more of the others, all as will be illustratively described herein, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawing,

Figure l is a diagrammatic representation of the apparatus and circuit arrangement of a preferred embodiment of the mechanical and electrical features of my invention, and

Figure 2 illustrates the magnetizing force-- flux density characteristic or so-called hysteresis loop of a part of the apparatus of Figure 1.

As conducive to a clearer understanding of certain features of my invention, it may at this point be noted that frequent occasion arises in practice for causing the repeated or cyclic actuation, for example of a signaling device such as a signal lamp, so that the successive periods of time during which the device is actuated are precisely of equal duration and the intervening time intervals are likewise precisely of equal duration and also so that the length of a time interval of actuation of the device bears an invariable ratio or proportion to the length of time of inaction of the device. For example, in flashing buoys, or the like, it is sometimes necessary to achieve identification of the buoy and hence of the point which it marks, by the length of the time interval of the flash and the length of the time period intervening the flashes; in such instances the time intervals must be invariable. One of the dominant aims of this invention is to provide a simple and thoroughly practical electrical system and apparatus for achieving thoroughly dependable and consistently precise control of such time intervals and of the relation or proportion of the time intervals of operation to the time intervals of inaction.

Referring now to the drawing and more particularly to Figure 1, there is diagrammatically indicated at Iii the device to be controlled, and for purposes of illustration, this device may be considered to be a signaling lamp that is to be cyclically operated, each cycle to include a time interval of illumination of the lamp followed by a time interval of darkness. It may further be assumed that the device iii is electrically operated or controlled and therefore has associated with it a circuit in which is included a suitable source of current conveniently taking the form of a storage battery ll and acircuit-controlling device comprising a fixed contact l2 and a movable switch member l3. Hence, where the device [0 is in the form of an incandescent lamp, the lamp is lighted for such a period of time as the switch l2l3 closes the circuit and remains dark for such a period of time as the switch I2-l3 is held open. These periods of time may be on the order of two or three seconds in duration.

The position of the switch member l3 with respect to the contact 12 is controlled by two coils 60 l4 and I5 operating upon an armature l6 conveniently pivoted as at H and having a portion adapted to engage-the switch member l3 to move the latter therewith. Preferably the movement of the armature l5 when the coils l4 and I5 are appropriately energized takes place in opposition to a spring l8 which is preferably adjustable. The coils l4 and [5 are related to the armature l6 so that when either coil alone is energized the armature [6 moves upwardly to close the switch I2-l3 and it remains in that position, thus holding the switch I2-|3 closed, as long as only one of the coils lt-I 5 is appropriately energized; the coils l4-l5, moreover, are related in opposition to each other so that, when the second of these two coils becomes appropriately energized, the armature 16 moves downwardly under the action of the spring l8, thus causing the switch member l3 to open the circuit of the device II]; the parts remain in downward position until one of the coils is deenergized so as to permit the other coil to attract the armature I6 and again cause the latter to close the switch l2-l3.

Considering now certain of the features of my invention whereby the duration of the circuitclosing action of the switch l2l3 and the duration of the circuit-opening action of the switch I2-l3 are predetermined and controlled, it might first be noted that I provide a polarized relay generally indicated at l9 arranged, in coaction with preferably certain other devices hereinafter more clearly described, to control the energization of the coils l4 and I5. The relay I9 has a movable armature 29 the movement of which is controlled by a coil 2 i, the relay being constructed and arranged in any suitable manner so that, when current of a certain value passes through the coil 2| in one direction, the armature 20 is moved to its extreme left-hand position, as viewed in Figure l, to make contact with a fixed contact 22 while, on the other hand, when current of a certain value passes through the coil 2| in reversed direction, the armature 23 is moved to its extreme right-hand position to make contact with a relatively fixed contact 23. As long as the current energizing the coil 2| is below the abovementioned certain value, the armature 20 remains in a neutral position between the contacts 22 and 23.

The current that energizes coil 2| of the relay I9 is derived from any suitable source but preferably from a storage battery 24 having therefore a low internal resistance and the battery 24 and coil 2| of the relay are connected in circuit with an inductance generally indicated at 25 wound upon or suitably associated with an iron core 26. As will be pointed out more clearly hereinafter and as conducive to a clearer understanding of certain features of my invention, it may at this point be noted that the inductance 25-26 is of suflicient value to cause the lapse of a substantial period of time between the closure of the circuit therethrough and through the relay coil 2| and the achievement of a current flow therethrough of a value suiiicient to cause the actuation of the relay armature 2G.

The circuits, however, in which the battery 24 may become effective are controlled, in accordance with certain features of my invention, preferably by the coils |4-| 5, and conveniently I provide suitable switch members and associated contacts appropriately related to the armature IE to cause actuation thereof by the latter. For example, I provide two switch members 21 and 28 connected, by the insulating bar 29, to the switch member l3. Thus actuation of the armature it causes also the actuation of the switch members 21 and 28.

Switch member 21 has associated with it a con- 5 tact 33 with which it is engaged when the switch I2-I3 is open, while switch member 28 has similarly related to it a contact 31 with which it engages when the switch l72--l3 is open. Upward movement of the switch member 27 brings it into 10 contact with a contact 322 while a contact 33 is positioned to be engaged by the switch member 28 upon upward movement of the latter.

The various switch members are conveniently made of a suitable spring sheet metal and the 15 various contacts coacting therewith, as above pointed out, are preferably carried by suitably yielding members which may also take the form of a spring sheet metal. The switch members i3, 21 and 28 are biased in any suitable manner 20 to tend to assume the position shown in Figure 1 in the drawing; this biasing action may be achieved by the spring i8 associated with the armature it but preferably the spring metal of the switch members themselves is made, in any 25 suitable manner, to tend to cause the switch members yieldingly to remain in the position shown in Figure 1.

Con-tact 33 is yieldingly held by its spring supporting member in the position substantially as 30 shown in Figure 1 while the spring supporting members of the contact: 3i, and SI are springbiased in an upward direction so that, when the switch members 2'! and are moved upwardly by the armature l8, contacts 30 and 3| follow 35 this upward movement throughout a portion thereof, the parts being so related that switch member 23 makes contact with the contact 33 just before the limit of upward movement of the contacts 33 and 31 is reached, thus causing the g closure of a circuit at the contact 33 before the circuit or circuits in which contacts 30 and 3! are included become broken by the continued upward movement of the switch members 21 and 28 respectively.

The spring member which supports the contact 33 and tends to hold it in the position shown in Figure 1 coacts with and contacts with a contact 34 as the continued upward movement of the switch member 28 picks up the contact 33 and its spring supporting member and carries the latter into engagement with the contact 34.

Before considering the various circuits with which the above-mentioned switch members and switch contacts are associated, it should be pointed out that Figure 2 represents the hysteresis loop of the iron core 26 associated with the inductive winding 25. The loop illustratively shown in Figure 2 is to be understood to be the flux density-field intensity characteristic of the iron core after suflicient reversals of the magnetizing field intensity have been achieved to prevent, upon further reversals, a shifting of the hysteresis loop relative to one of the axes; the loop will be seen to be symmetrical with respect to both the ver- 05 tical and the horizontal axis.

The abscissa: represent the magnetizing force or magnetic field intensity which is, of course, a function of the current flowing through the winding 25 related to the core 28. ordinates reprcsent the density of magnetic flux in the iron core 26.

Assuming that the maximum magnetizing force, corresponding, of course, to the maximum value of current in the coil 25 in a positive direc- 15 tion, is equivalent to the value 0G, the flux density in the iron core 26 corresponding thereto is represented by the value BG; if the magnetizing force or the current in the winding 25 is now diminished and brought to zero, the flux density in the iron core 26 still has a very substantial value and will be seen to be equal to OC; this value is known as the remanent magnetism. To reduce the flux density in the core 26 to zero, the field intensity has to be reversed, that is, the current through the winding 25 must be reversed, and brought to a value equivalent to OD, corresponding to the abscissa of the point where the left-hand part of the curve crosses the horizontal axis or the axis of field intensity. This value OD of the field intensity necessary to reduce the flux in the core 26 to zero is known as the coercive force. The hysteresis loop of Figure 2 thus represents the relation between fiux density in the iron core 26 and the magnetizing force or field intensity, the latter a function of the current flowing through the winding 25, between two assumed maximum values of magnetizing force or current in the winding 25, the one maximum being represented by a value corresponding to 0G in the positive direction and the other maximum being represented by the value OJ in the negative direction. With this preliminary consideration of the hysteresis loop of the iron core associated with the inductive winding 25, the various circuits associated with the above-described switching mechanism and related parts may now be considered in detail.

Let it first be assumed that the mechanically movable parts have just been brought into the positions shown in Figure 1; the switch |2|3 is open and the device ID, if a signal lamp, remains in darkness, and the armature 20 of the polarized relay l9 stands in its neutral position. Let it be assumed that, at this time, the flux density in the core 26 is represented by the value OF, in a negative direction. This relation of the parts brings about a closure of a circuit, in which is included the battery 24, the polarized relay winding 2| and the winding 25. This circuit may be traced from one terminal of the battery 24, conductor 35, switch member 28, contact 3|, conductor 36, coil 2| of the polarized relay l9, winding 25, adjustable tap 31, conductor 38, contact 36, switch member 21 and by way of conductor 39 back to the other terminal of the battery.

The current that commences to flow through the winding 25, in the above-outlined circuit, produces a magnetizing force in a positive direction,

- assuming ultimately a maximum value equivalent to 0G (see Fig. 2). It has, however, taken a considerable period of time, from the moment of closure of the above-described circuit, for the achievement of this maximum value of current in the circuit. The time rate of rise of current in this circuit is relatively very low; the rise or increase in the current is opposed not only by the inductance and resistance in the circuit but also by the remanent magnetism in the iron core. The flux due to this remanent magnetism in the iron core 26 is in a direction opposed to that produced by the current flowing in this circuit;

referring to Figure 2, the remanent magnetism,

represented by the ordinate OF, is not reduced to zero until the current or magnetizing force has achieved a value 0A. Continued increase in the current or magnetizing force in the winding 25 (from the value 0A to the value 0G) is accompanied by the production, in the iron core 26, of a flux density equivalent to the ordinate BG. During this prolonged interval of time, the iron in the core 26 has gone through the portion FAB of the hysteresis loop.

When the current has finally achieved a value equivalent to 0G, the polarized relay I9 is actu- 9 ated to swing the armature 20 toward the left and hence to close a circuit atthe contact 22. The circuit thus closed includes the battery 24 and the coil l4 and will be seen to be as follows: From the upper terminal of the battery 24, con- 10 ductor 40, contact 22, armature 20, conductor 4|, conductor 42, coil l4, and then by way of conductor 43 to the remaining terminal of the battery 24.

Coil |4 starts to swing the armature l6 up- 15 wardly, the latter moving with it the switch members l3, 2'! and 28, but before switching members 27 and 25 are moved out of contact with the contacts 36 and 3|, respectively, switch member 28 has engaged the contact 33 to hold closed 20 the circuit of coil 4 initially closed by the relay armature 20 at the contact 22.

The energizing circuit of coil I4 is thus maintained closed independently of the armature 20 and contact 22 of the polarized relay l9 and this 25 takes place through the following circuitz-From one terminal of the battery 24, conductor 35, switch member 28, contact 33, conductor 44, conductor 42, coil l4, and then by way of conductor 43 back to the other side of the battery 24. 30

After switch member 28 has engaged contact 33, the switch members 28 and 21 are moved out of engagement with contacts 3| and 30, respectively, whereupon continued upward movement brings the switch member 2! into engagement .35 with the contact 32 while the spring member 45 which carries the contact 33 has been brought into engagement with contact 34.

The disengagement of the switch members 28 and 21 from the contacts 3| and 30, respectively, 40 has caused the interruption of the circuit in which was included the battery 24, the winding 2| of the polarized relay l9, and the inductance 2.5. The current in this circuit, up tothis time having a value corresponding to the abscissa 0G 45 of Figure 2, drops to zero, and the flux density of the iron core 26, up to that time being at a. value corresponding to the ordinate GB, drops, along the portion BC of the hysteresis loop, to a value, in the positive direction, equivalent to 50 the ordinate 0C, this value representing the remanent magnetism in the core 26.

Though the current in the relay coil 2| has dropped to zero so that the armature 20 cannot. be held in engagement with the contact 22, the circuit of coil I4 is, nevertheless, maintained energized, as above described in detail, at the contact 33.

The upward movement of the armature l6 was. accompanied also by the closure of the switch |2--|3, thus closing the circuit of the signaling device It! and causing its illumination where it takes the form of a lamp.

Following the interruption of the energizing circuit of inductance 25 there took place a 010- sure of a circuit for again energizing the inductance 25 but so that the new energizing current flows through the inductance 25 in a direction opposite from that in which it passed therethrough in the circuit initially described above.

This new energizing circuit may be traced as followsz-From the upper terminal of battery 24, conductor 35, switch member 28, contact 33, switch member 45, contact 34, conductor 46, ad-

justable tap 41 at the lower end of the inducg5 tance 25, inductance 25, coil 2| of the relay I9, conductor 36, conductor 48, contact 32, switch member 21, and then by way of conductor 39 back to the other side of the battery 24.

The closure of this circuit finds the iron core 26 with a remanent magnetism equivalent to the ordinate DC of Figure 2 to overcome which a. substantial coercive force is needed. The flux corresponding to this remanent magnetism 0C is, moreover, in a direction opposite to that which the rising current in the winding 25 produces, the current passing through the latter in reversed direction or in negative direction as considered in Figure 2. This remanent flux 0pposes the increase of the current through the winding 25 in the negative direction and considerable time has elapsed before the current has increased in a negative direction to the value OD of Figure 2 in order to reduce this remanent flux 00 to zero, along the portion CD of the hysteresis characteristic of the iron core 26.

From that point on the current continues to increase in a negative direction from the value OD to the value OJ, producing a fiux density, now in a negative direction, increasing from zero, along the portion DE of the characteristic, to a value equivalent to the ordinate JE.

The time rate of rise of the current, in this negative direction, from a zero value to the value OJ has been very low and the corresponding time interval during which this rise takes place relatively long. This long time interval, like the time interval required to cause a transition in the conditions of the inductance along the portion FAB of the characteristic, is due, not merely to the low time rate of increase of current due to the factors of resistance and inductance in the circuit, the effect of these factors being greatly increased because of the relation to the winding 25 of an iron core of high magnetic permeability, but also due to the fact that the current must first overcome the eifect of the very substantial remanent magnetism that is made to act in a direction to oppose the magnetizing force produced by the increasing current.

When the current, in the negative direction, has reached a value OJ, the relay winding 2| is sufficiently energized to move the armature 2B; but the current now passes through the winding 2| in reversed direction and hence the armature 20 is moved toward the right and into engagement with the contact 23, thus closing a circuit in which is included the coil l5.

This circuit may be traced as follows:--From the upper terminal of battery 24, conductor 35, switch member 28, contact 33, switch member 45, conductor 44, conductor 4i, armature 20, contact 33, conductor 49, coil l5 and thence by way of conductor 43 back to the other side of the battery 24.

Coil l5 thus becomes energized, the circuit of coil I4 having, during this time interval, been held closed at the contacts 28-33 through a circult which, as noted hereinabove, extends from the upper terminal of the battery 24, conductor 35, switch member 38, contact 33, switch member 45, conductor 44, conductor 42, coil l4, and thence by way of conductor 43 back to the other terminal of the battery. Coils i4 and I5, however, act in opposition to one another and hence the armature I6, under the action of the spring l8 or under the action of the spring switch members I3, 21 and 2B, or both, moves downwardly so that the parts assume the position shown in Figure 1 of the drawing. The current flowing through the inductance 25 thus becomes interrupted at the contacts 45-34 so that, referring now to Figure 2, the energizing current OJ is reduced to zero and the flux density in the iron core 26 is reduced from the value JE to the value OF, the reduction taking place along the portion EF of the hysteresis loop. The iron core 26 is thus left in a condition in which it possesses a remanent magnetism, in a negative direction, equivalent to the value OF.

The movement of the switch members, under the control of the coils i4l5, into the position shown in Figure 1, will be seen to eiiect an opencircuiting, at the switch members l2-l3, of the circuit of the signaling device Iii so that the latter, illustratively taking the form of a lamp, is put out and is in darkness; by way of switch members 28 and l and their respectively associated contacts 3i and 38, there is new again closed an energizing circuit in which is included the inductance 25 and the relay winding 2 I, all as hereinabove initially described. This energizing circuit, however, is completed in such a way that the current flowing through the inductance 25 is now reversed; in other words, referring to Figure 2, the current in this newly established energizing circuit, instead of increasing in the direction OJ, increases in the direction 06. But its rate of increase is very slow due, aside from other factors, to the very substantial remanent flux OF remaining in the iron core 25 before this energizing circuit was closed and which acts in a direction opposed to the flux produced by this increasing current. Reference to Figure 2 shows that a current, now in this reversed or positive direc tion, equivalent to the value 0A must be achieved before this remanent magnetism OF is reduced, along the portion FA oi the characteristic, to zero, whereupon further increase in this current, from the value GA to the value OG, is effective to produce a ilux density in the iron core 26 equivalent to the value GB, the flux density increasing along the portion AB of the characteristic.

The cycle of operations above described in detail repeats itself as will now be clear in view of the foregoing, though it might be noted that the achievement of a value of current for which the relay I9 is set, illustratively a current value of 0G, causes the relay to close the circuit at the contact 22 for energizing the winding M, where-' upon the armature I5 and related parts become actuated with detailed results and actions as fully described above.

With this arrangement I am enabled to achieve time intervals in the cyclic control 01' the device l0 that are of very substantial length. I am enabled, due to certain features of my invention, to make an inductance cause a vastly lower rate of increase in current therethrough than has heretofore been possible and to cause the coacting mechanisms to achieve vastly longer time intervals in the actuation of the device 10 than has heretofore been possiblev The current from the direct current source, such as the storage battery 24, finds the inductance 25-26, as it starts to pass through the winding 25, in a condition where the iron core 26 has a remanent magnetism or flux density which the current, tending to increase, must oppose and negative by its own flux before it can produce, in the iron core 26, a flux acting in the direction of its own flux. This operation consumes a considerable period of time.

At each cycle, the current that is to pass through the inductive winding 25 must first oppose and bring to zero a substantial remanent flux in the iron core before it can magnetize the core itself. For example, the current flowing in the positive direction to achieve a value 0G, referring to Figure 2, must reverse the magnetic flux in the iron core 26 from the remanent flux value OF (which is in a negative direction) to the value GB (which is in a positive direction), the transition in the magnetic condition of the iron core 25 taking place along the portion FAB of the characteristic. In like manner the reversed current, during the next cycle of operation, increasing in a direction OJ, must reverse the flux from the remanent flux value 00 (in a positive direction) to a flux value of JE (which is in a negative direction), the transition taking place along the portion CDE of the characteristic.

In this manner I can obtain time intervals in the actuation of a device like that indicated at ID on the order of two or three seconds, by way of example.

Moreover, by adjusting the position of the adjustable taps Al and 31, I am enabled to give the intervals of closure of the circuit of the device it) at the contacts l2l3 and of opening of that circuit at these contacts any desired ratio. For example, if I wish to have the interval of illumination of the signal lamp of the same length as the interval of darkness thereof, I position the adjustable taps 3i and 41 at the same point along the inductance 25 so that there is included the same number of turns of the inductance 25 for .each of the two portions of the cycle of opera tion. In other words, the current increasing in a direction toward 0G of Figure 2 is opposed by the same factors, particularly the factors of inductance and resistance, that oppose the increase in the current in the opposite direction or in a direction OJ.

On the otherhand if I wish to make one of these intervals longer than the other, I position one tap so that there is included in the circuit, during one portion of the cycle of operation, more inductance and resistance than there is included in the other portion of the cycle. For instance, if I wish to have the signal lamp illuminated for a period of one second followed by an interval of darkness of two seconds, I position the taps so that the circuit in which is included the tap has included in it substantially one-half of the inductance and resistance that is included in the circuit in which is included the tap 3?.

Thus it will be seen that there has been provided in this invention a method and apparatus in which the several objects hereinbefore noted, together with many thoroughly practical advantages, are successfully achieved. It will be seen that the apparatus is of a thoroughly practical nature, is capable of embodiment in inexpensive and thoroughly dependable and rugged form, and is well adapted to meet the varying conditions of hard practical use.

As many possible embodiments may be made of the mechanical features of the above invention and as the art herein described might be varied in various parts, all without departing from the scope of the invention, it is to be understood that all matter hereinabove set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. In apparatus of the character described, in combination, an inductive winding and a core of magnetic material therefor; a source of direct current; a polarized relay adapted to be actuated upon the achievement through the coil thereof of a certain current value; switching means including coacting contacts with some of which said switching means is engageable when in one position and with others of which said switching means is engageable when in another position; circuit connections between said source, said winding, said coil, said contacts, and said switching means whereby, when said switching means is in one position, a circuit is completed and the current from said source passes through said winding and said coil in one direction and when said switching means is in said other position a circuit is completed in which the direction of current flow through said winding and said coil is reversed; means including a coil for moving said switching means into one position, means whereby said coil is controlled by said relay; means including a part of said switching means for maintaining effective the energizing circuit of said last-mentioned coil after the latter has moved said switching means; and another coil with means whereby it is controlled by a subsequent actuation of said polarized relay and adapted when energized to oppose said last-mentioned coil, whereby said switching means moves into its other position.

2. In apparatus of the character described having a device adapted to assume two conditions, each for a certain time interval, in combination, means for controlling said time intervals, said means including an inductive winding and an iron core therefor, a source of current for energizing said winding, said winding and said core being so proportioned with respect to the voltage of said source of current that the time rate of rise of current through said winding is low, means responsive-to the rise to a certain value of said energizing current for altering the condition of said device, and means for reversing the direction of current flow through said inductive winding after each effected change in condition of said device.

3. In apparatus of the character described having a device adapted to assume two conditions, each for a certain time interval, in combination, means for controlling said time intervals, said means including an inductive winding and an r iron core therefor, a source of current for energizing said winding, means responsive to the rise to a certain value of said energizing current for altering the condition of said device, means for reversing the direction of current flow through said inductive winding after each effected change in condition of said device, and means for changing at will the ratio of the inductance efiective when current flows through said winding in one direction to the inductance elfective when current flows in reversed direction.

i. In apparatus of the character described, in combination, means for causing a delay in the rise of current in a circuit including a source of uni-directional current and an inductive winding related to a core of magnetic material, said means including switching means for reversing the direction of current flow in said circuit, means responsive to a condition caused by a certain value of current flow in said circuit for controlling said switching means, and means including said winding and said core for making the time-constant of said circuit different when the current flows therethrough in one direction from the time-constant of said circuit when the current flows therethrough in reversed direction.

5. In a signaling device which is to be operated so that periods of actuation and of inaction of said device follow alternately upon each other and in continued succession, of means for controlling the time interval of actuation of said device and the time interval of inaction of said device, said means including a circuit in which is included a source of uni-directional current and an inductive winding having a core of magnetic material related thereto, and means for repeatedly energizing said circuit with a current flow in such a direction that the rising current through said inductive winding is in opposition to the remanent magnetism of said core, and means operating in substantial synchronism with the periodic energization of said inductive winding for controlling said signaling device.

6. In a signaling device which is to be operated so that periods of actuation and of inaction of said device follow alternately upon each other and in continued succession, of means for controlling the time interval of actuation of said device and the time interval of inaction of said device, said means including a circuit in which is included a source of uni-directional current and an inductive winding having a core of magnetic material related thereto, means responsive to the achievement of a certain value of current in said circuit for reversing the direction of current flow therethrough, and means causing actuation of said signaling device during current flow in said circuit in one direction and inaction of said signaling device during current flow in reversed direction in said circuit.

'7. In a signaling device which is to be operated so that periods of actuation and of inaction of said device follow alternately upon each other and in continued succession, of means for controlling the time interval of actuation of said device and the time interval of inaction of said device, said means including a circuit in which is included a source of uni-directional current and an inductive winding having a core of magnetic material related thereto, means responsive to the achievement of a certain value of current in said circuit for reversing the direction of current flow therethrough, means causing actuation of said signaling device during current flow in said circuit in one direction and inaction of said signaling device during current flow in reversed direc tion in said circuit. and means including a part of said inductive winding and core causing said circuit to have a time-constant when current flows therethrough in one direction different from the time-constant when current flows in reversed direction.

8. A device constructed to assume alternately two positions and having means for holding said device in one position for a certain time interval and for holding it in its other position for a certain time interval, said means including in combination a circuit having included therein a source of uni-directional current and an inductive winding having a core of magnetic material related thereto, means responsive to the direction and to a certain value of current flow in said circuit for reversing the current flow therein and for controlling the positions of said device, and means including a part of said inductive winding and core causing the rate of current rise to be diiferent when said circuit is conditioned for flow of current in one direction from the rate of rise of current when said circuit is conditioned for current flow in reversed direction.

9. In a circuit including a source of electrical energy, current delay means comprising an inductive winding, an iron core of high remanent magnetism coacting therewith, means for giving the magneto-motive-force produced by the current through said winding such a direction as to oppose the remanent magnetism of said core, and means causing more turns of said winding to be eifective when current flows therethrough in one direction than are effective when current flows in the opposite direction, for giving a greater delay in the building-up of current in said one direction than the delay in building-up 01' current flowing in the opposite direction.

10. In apparatus of the character described, in combination, a source of current, a movable member capable of assuming either of two positions, two magnetic circuits, one of which has related thereto a movable armature subjected to the flux thereof, winding means connected to said source of current and associated with said two magnetic circuits, switching means interposed between said winding means and said source for reversing the direction of current flow through said winding means and capable of being actuated to interrupt the current flow through said winding means at a point such that substantial remanent magnetism remains in said other magnetic circuit, whereby a subsequent energize.- tion of said winding means takes place in a direction of current flow such that the flux produced by said winding means is in opposition to said remanent magnetism, and means including said movable armature for changing the position of said switching means when said current reaches a certain value corresponding to said point.

11. In apparatus of the character described having a device adapted to assume two condi-- tions, each for a certain time interval, comprising, in combination, a movable member capable of assuming either of two critical positions, means responsive to changes in the said positions of said movable member for correspondingly changing the condition of said device, and means for controlling the time intervals allotted respectively to the two conditions of said device, said controlling means comprising (1) a source of uni-directional current, (2) a core of magnetic material, (3) a winding related to said core, (4) reversing-switch means interposed between said winding and said source for reversing the direction of current flow through said winding, said movable member being of magnetic material, (5) means producing a magnetic field of fixed direction, and (6) fluxproducing means responsive to a function of the current energizing said winding for coacting with said magnetic field of fixed direction to produce a composite magnetic field, said movable member of magnetic material being subjected to and moved in accordance with changes in said composite field.

12. In apparatus of the character described having a device adapted to assume two conditions, each for a certain time interval, comprising, in combination, a movable member capable of assuming either of two critical positions, means responsive to changes in the said positions of said movable member for correspondingly changing the condition of said device, and means for controlling the time intervals allotted respectively to the two conditions of said device, said controlling means comprising (1) a source of unidirectional current, (2) a core of magnetic material, (3) a winding related to said core, (4) reversing-switch means interposed between said winding and said source for reversing the direction of current flow through said winding, and (5) means responsive to the achievement through said winding of a certain value of current for moving said movable member from one of said critical positions to the other.

13. In apparatus of the character described having a device adapted to assume two conditions, each for a certain time interval, comprising in combination, a source of direct current, a fluxresponsive control member movable into either of two critical positions, means changing the condition of said device in accordance with movement of said control member into said two critical positions, and means for controlling the lengths of time intervals allotted respectively to the two conditions of said device, said controlling means comprising (1) flux-producing means, said member being exposed to the flux thereof, (2) an iron core, (3) a winding about the latter and capable, when energized, to magnetize said core and said core being capable, when said winding is deenergized, of retaining residual magnetism, (4) reversing-switch means interposed between said source and said winding and capable of interrupting the current flow through said winding and then reversing the direction of current flow therethrough, (5) a winding energized from said source and having said reversing-switch means interposed between it and the source and positioned to affect the flux of said flux-producing means, and (6) means for actuating said switching means in response to the positions assumed by said flux-responsive movable member.

14. In apparatus of the character described, having a device adapted to assume two conditions. each for a certain time interval, comprising, in combination, a source of direct current, a fluxresponsive control member movable into either of two critical positions, means changing the condition of said device in accordance with movement of said control member into said two critical positions, and means for controlling the lengths of time intervals allotted respectively to the two conditions of said device, said controlling means comprising (1) flux-producing means, said memher being exposed to the flux thereof, (2) an iron core, (3) a winding about the latter and capable, when energized, to magnetize said core and said core being capable, when said winding is deenergized, of retaining residual magnetism, (4) reversing-switch means interposed between said source and said winding and capable of interrupting the current flow through said winding and then reversing the direction of current flow therethrough, (5) means for actuating said switching means in response to the positions assumed by said movable member, and (6) means whereby current flowing through said winding affects the flux of said flux-producing means, thereby to efiect change in the position of said movable member.

15. In apparatus of the character described in which there is a device adapted to assume alternately two conditions and means for controlling the time intervals during which said device assumes said two conditions respectively, in which the said controlling means comprises, in combination, a core of magnetic material, a winding for said core, a source of uni-directional current for energizing said winding, reversing-switch means interposed between said source and said winding and capable, when actuated, of interrupting the current flow through said winding and then reestablishing a current flow through said winding but in reversed direction, the material of said core being of relatively high magnetic retentiveness, and means operating each time that said core achieves a certain degree of magnetization for actuating said reversingswitch means to thereby cause the latter to interrupt the current flow whereby said magnetization is achieved, thereby to leave said core with substantial remanent magnetism therein, and to cause the energization of said winding in said reversed direction to have to overcome the efiect of said remanent magnetism.

16. In apparatus of the character described, in which there is a device adapted to assume alternately two conditions and ,means for controlling the time intervals during which said device assumes said two conditions respectively, in which the said controlling means comprises, in combination, a core of magnetic material, a winding for said core, a source of uni-directional current for energizing said winding, reversingswitch means interposed between said source and said winding and capable, when actuated, of interrupting the current flow through said winding and then reestablishing a current flow through said winding but in reversed direction, the material of said core being of relatively high magnetic retentiveness, electromagnetically-acting means capable, in accordance with changes in magnetomotive forces thereof, to operate said reversing-switch means, and means operating each time that there is achieved a certain value of magnetization of said iron core to change the magnetomotive force of said electromagneticallyacting means.

17. In an apparatus of the character described, an inductance having a core of magnetic material and a winding, a source of direct current, a polarized relay having an armature capable of assuming either of two positions in response to the achievement through the coil thereof of a certain value of current, switching means capable of assuming either of two positions, means connecting said relay, inductance, switching means and source of current so that current flows through said relay coil and inductance in one direction in one position of said switching means and in the opposite direction in the other position of said switching means, means including certain of said connections and said relay for causing-said switching means to assume one position when the current flowing through the relay coil in one direction reaches said certain value and for causing said switching means to assumeits other position when the current through the relay coil reaches said certain value in said opposite direction.

18. In a device as set forth in claim 1'7, means for selectively changing the ratio of the value of said inductance when current flows in one direction therethrough to its value when current flows in the opposite direction therethrough.

FRANK W. GODSEY, JR. 

